There have been numerous attempts to provide improved and enhanced ignition systems for internal combustion engines. These prior systems have, in particular, been designed for the ignition spark type engines and include various types of electronic circuits for effecting control over the ignition as well as to provide enhanced ignition power. Some of the previously known circuits have attempted to enhance ignition of the fuel air mixture through forming multiple firing pulses at an ignitor for a particular engine cylinder. An example of such a system is shown in U.S. Pat. No. 3,394,690 granted to L. W. Bell on July 30, 1968. That illustrative system includes circuitry designed to produce a series of firing pulses that are applied to the ignitors or spark plugs. The objective is to provide multiple pulse firing comprising a sequential series of ignition sparks occurring at predetermined spaced times during the firing or ignition stroke to better assure that the fuel-air mixture is ignited to achieve more efficient use of fuel than could be expected to be achieved through the use of an ignitor providing only a single spark at the predetermined ignition time. Such multiple pulse firing is particularly advantageous when the engine is in an acceleration mode of operation.
Another attempt to enhance performance of internal combustion engines has been the providing of individual spark ignition coils for each of the cylinder ignitor devices. Examples of such attempts are disclosed in U.S. Pat. No. 3,993,035 granted to M. E. Gerry on Nov. 23, 1976 and U.S. Pat. No. 3,886,923 granted to the same inventor on June 3, 1975.
A different approach in attempting to obtain enhanced ignition of the fuel-air mixture within the cylinder has been attempted through modification of the electric firing pulse to achieve improved ignition of the fuel-air mixture by extending the duration of ignition spark. An example of this type of approach is illustrated in U.S. Pat. No. 3,939,814 granted to R. E. Bergstresser on Feb. 24, 1976.
Other known electronic ignition systems that have been devised are directed to systems which substitute electronic circuitry for the older and more frequently utilized mechanical apparatus for effecting the ignition. The general objective of these circuits is to merely eliminate the mechanical malfunctions that could otherwise be expected utilizing mechanically operated apparatus components. While the electronics technology enables achievement of this objective, such circuits have become relatively complex in attempting to incorporate sophisticated circuitry capable of compensating for advancement or retarding of the firing point as well as also determining the time of firing.
In general, the previously devised electronic systems for internal combustion engine firing have been directed to circuitry incorporated in apparatus of a type that is generally intended to be substituted for the apparatus previously utilized and employing mechanically actuated components. These systems, by and large, have not provided any distinct change in the mode of operation of providing the firing pulses although the substitution of the electronic circuits for the mechanical components has been effective in eliminating the mechanical malfunctions that were previously frequently experienced.